Cortaderia plant named ‘Silver Star ’

ABSTRACT

A new variety of  Cortaderia  plant particularly distinguished by having a broad inverted triangle shape with arching leaves and greyed-green inflorescences, long green leaves with yellow-green stripes, moderate vigor and hardiness to at least USDA zone, is disclosed.

Genus/species: Cortaderia selloana.

BACKGROUND OF THE INVENTION

The present invention comprises a new and distinct cultivar of pampasgrass, botanically known as Cortaderia selloana, and hereinafterreferred to by the cultivar name ‘Silver Star’. The new cultivaroriginated as a whole-plant mutation from Cortaderia selloana ‘Pumila’(unpatented). The new cultivar was found in the breeder's nursery inBoskoop, The Netherlands, in 2000.

The new cultivar was created in 2000 and has been asexually reproducedrepeatedly by division in Boskoop, The Netherlands over a five-yearperiod. ‘Silver Star’ has not been observed under all possibleenvironmental conditions. The present invention has been found to retainits distinctive characteristics through successive asexual propagations.

Plant Breeder's Rights for this cultivar were applied for with theEuropean Union on Jan. 24, 2006.

SUMMARY OF THE INVENTION

The following are the most outstanding and distinguishingcharacteristics of this new cultivar when grown under normalhorticultural practices in Boskoop, The Netherlands:

-   -   1. A perennial with a broad inverted triangle shape with arching        leaves and greyed-green inflorescences;    -   2. Long green leaves with yellow-green stripes;    -   3. Moderate vigor; and    -   4. A hardiness to at least USDA zone 7.

DESCRIPTION OF THE PHOTOGRAPHS

This new Cortaderia plant is illustrated by the accompanying photographswhich show overall plant habit including inflorescence, and foliage ofthe plant; the colors shown are as true as can be reasonably obtained byconventional photographic procedures. The photographs are from a wholeplant about two-years old and grown in a 19-cm pot outdoors in Boskoop,The Netherlands.

FIG. 1 shows the overall plant habit, including the inflorescence andthe foliage.

FIG. 2 shows a close-up of the mature inflorescence.

FIG. 3 shows a close-up of the foliage.

DETAILED DESCRIPTION OF THE NEW PLANT

The following detailed descriptions set forth the distinctivecharacteristics of ‘Silver Star’. The data which define thesecharacteristics were collected from asexual reproductions carried out inBoskoop, The Netherlands. The plant history was taken on two-year oldplants in 19-cm pots in September that were grown outdoors at atemperature range of 4° C. to 32° C. Color readings were taken undernatural light outdoors. Color references are primarily to The R.H.S.Colour Chart of The Royal Horticultural Society of London (R.H.S.)(2001).

-   Classification:    -   -   Family.—Poaceae.        -   Botanical name.—Cortaderia selloana.        -   Common name.—Pampas grass.-   Parentage: Whole plant mutation arising from Cortaderia selloana    ‘Pumila’ (unpatented).-   Growth:    -   -   Type.—Herbaceous perennial.        -   Shape.—Broad inverted triangle with arching leaves and            inflorescences on top.        -   Growth habit.—Broad with arching leaves.        -   Growth rate.—In the Spring, about 20 cm per month.        -   Height (excluding inflorescences).—86 cm.        -   Height (including inflorescences).—105 cm.        -   Width.—105 cm.        -   Vigor.—Moderate.        -   Outdoor plant performance.—Use in container planting or in            flower beds.        -   Time to produce a finished flowering plant.—Average of 9            months.        -   Hardiness.—Tolerant to at least USDA zone 7.        -   Root description.—Not fibrous, moderately fleshy.-   Leaves:    -   -   Arrangement.—Alternate.        -   Type.—Single.        -   Quantity per branch.—10.        -   Attachment.—Leaf sheaths grow to the base of the shoots; the            average width of the sheath is 1.2 cm (when folded open) and            RHS 146D (yellow-green) and with a tinge of RHS 179D            (greyed-red) at the base.        -   Shape.—Linear.        -   Apex.—Long acuminate.        -   Base.—Cuneate, leaves sheathing.        -   Margin.—Entire but very sharp when rubbed downwards due to            very small and sharp teeth with about 18 teeth per            centimeter.        -   Texture.—Slightly glossy and smooth; ligules sparsely            covered with very RHS 156C to RHS 156D (greyed-white) hairs            that are an average of 0.2 cm in length.        -   Length.—59.5 cm.        -   Width.—0.85 cm.        -   Venation.—Parallel.        -   Vein color.—Upper surface: RHS 137C (green) and outer margin            is RHS 155A (white) and striped lengthwise with RHS 190B to            RHS 190C (greyed-green). Lower surface: RHS 137A to RHS 137B            (green) and striped lengthwise RHS 138A to RHS138B and the            outer margin is RHS 157A (green-white).        -   Color.—Young leaves: Upper surface: RHS 137C (green) and            striped lengthwise with RHS 145B to RHS 145C (yellow-green).            Lower surface: RHS 143A (green) and striped lengthwise with            RHS 145A (yellow-green). Mature leaves: Upper surface: RHS            137C (green) and outer margin is RHS 155A (white); the leaf            blade is striped lengthwise with RHS 190B to RHS 190C            (greyed-green). Lower surface: RHS 137A to RHS 137B (green);            the leaf blade is striped lengthwise RHS 138A to RHS 138B            and the outer margin is RHS 157A (green-white).        -   Durability of leaves to stress.—Very high.-   Stems:    -   -   Branching habit.—Grass-like plant with basal branching; main            herbaceous shoots grow from the base; no lateral branching.        -   Basal stems.—Appearance: Rounded, somewhat flattened and            slightly glossy. Quantity: Average number of stems is 19.            Strength: Very strong. Diameter: 0.5 cm to 0.6 cm; shoots            are somewhat flattened. Length: 14.3 cm. Texture: Smooth            with no pubescence. Color: RHS 146D (yellow-green) with RHS            179D (greyed-red) tinged at the base.        -   Internode length.—2.5 cm.-   Flower buds:    -   -   Quantity per basal stem.—10,000.        -   Shape.—Lanceolate.        -   Length.—0.4 cm and enclosed by 1 glume and many lemma.        -   Diameter.—0.1 cm.        -   Color.—RHS 145A (yellow-green); glumes and lemma are RHS            196D to RHS 197D (greyed-green).-   Inflorescence:    -   -   Arrangement.—Terminal panicle.        -   Aspect.—Upright to slightly outward.        -   Flowering habit.—Flowers continuously from late August to            late October; flowers are persistent.        -   Lastingness of flowers on the plant.—10 days.        -   Rate of flower opening.—After the first flowers open, all            flowers will open within two weeks.        -   Inflorescence height.—34.9 cm.        -   Inflorescence width.—11.2 cm.        -   Inflorescence shape.—Feathery.        -   Fragrance.—Absent.        -   Diameter.—0.2 cm.        -   Depth (height).—0.4 cm.        -   Quantity per inflorescence.—Over 10,000.        -   Quantity per basal stem.—10,000.-   Flowers:    -   -   Shape.—Single and grass-like.        -   Flower type.—Single (enclosed by 1 glume and many lemma).        -   Color (when opening).—Both upper and lower surfaces: RHS            196C to RHS 196D (greyed-green).        -   Color (fully opened).—General: Color is greyed-green and            does not fade. Both upper and lower surfaces: RHS 196D to            RHS 197D (greyed-green).        -   Glume.—Quantity per flower: One. Arrangement: One glume            positioned at posterior of the flower. Apex: Narrow acute.            Margin: Entire. Shape: Linear. Length: 1.5 cm. Diameter:            0.05 cm. Texture: Smooth and moderately glossy.        -   Lemma.—Quantity per flower: 50. Arrangement: Lemma rotate            around flower. Shape: Hair-like. Margin: Entire. Length:            1.5 cm. Diameter: 0.01 cm. Texture: Pubescent.        -   Peduncle.—Length: 66 cm. Diameter: 0.9 cm. Angle: Zero            degrees, vertical. Strength: Strong. Color: RHS 138B            (green).        -   Pedicel.—Length: 0.2 cm. Diameter: 0.05 cm. Angle: Five            degrees. Strength: Strong. Color: RHS 144C (yellow-green).-   Reproductive organs:    -   -   Stamens.—Quantity: 2. Anther shape: Basifixed, feather-like.            Anther length: 0.12 cm. Anther color: RHS 145D            (yellow-green). Pollen color: RHS N167A to RHS N167B            (greyed-orange). Pollen amount: Scarce.        -   Pistils.—None observed.        -   Ovary color.—RHS 146D (yellow-green).-   Fruit and seed set: Has not been observed.-   Disease and insect resistance: No more susceptible to pests and    diseases than other Cortaderia varieties.

COMPARISON WITH PARENTAL AND COMMERCIAL CULTIVARS

‘Silver Star’ differs from the mutation parent ‘Pumila’ (unpatented) inthat ‘Silver Star’ has green foliage with yellow-green stripes, while‘Pumila’ has green foliage with no stripes or markings.

‘Silver Star’ differs from commercial cultivar ‘Splendid Star’ (U.S.Plant Pat. No. 16,277) in that ‘Silver Star’ exhibits no fragrance,while ‘Splendid Star’ has a slight fragrance. Further ‘Splendid Star’has a golden-yellow variegation, whereas ‘Silver Star’ has a white togreen-white variegation.

1. A new and distinct variety of Cortaderia plant as shown and describedherein.